1. Field of the Invention
This invention relates to farming equipment, and more particularly, to an improved apparatus for preparing a seed bed and rooting environment prior to planting.
2. Description of the Related Art
This invention is an improvement over known soil conditioning apparatus, including that described in U.S. Pat. No. 4,055,126, issued 27, Oct. 1977 to Jerrell Harden and Ronald Brown, and in U.S. Pat. No. 4,187,916, issued 12, Feb. 1980 to Jerrell W. Harden and William P. Brown. Hereinafter for convenience, the devices described in the aforementioned Brown et al '126 and Harden et al '916 patents are called collectively the "Harden-Brown soil conditioning apparatus".
Farmland that has been cultivated (plowed) or had any traffic on it will form a compacted layer at or beneath the surface. This compacted layer of soil is called a "plow pan" or "hard pan" or surface compaction. The naturally occurring "hard pan" or man-made "plow-pan" is usually about 1/2 to 4 inches thick and may be located about 6 to 20 inches beneath the surface, while surface compaction is in the top 8 inches. There are two main factors that contribute to the development of a compacted layer. One is the weight of the implements used to till the soil. The other is the weight of the tractor creating forces acting through the wheels. As the tractor moves across the field, "traffic pans" are created under the tractor wheels. As the "traffic pans" are tilled, they move further down until they reach a depth where it becomes difficult for a plow to disturb them. When soil is loose, one pass across it with a farm tractor will produce 60 to 80 percent of maximum soil compaction. Thereafter, all successive passes can compact it only 20 to 40 percent tighter.
The majority of cultivated land in this country does not necessarily require deep plow subsoiling to break up the subsurface hard pan. Much of the soil can be cultivated to a depth of about 4 to 8 inches; this will be sufficient to promote effective root growth. No previously available no-till planters have the capability to plow or loosen up this surface 4 to 8 inches in the row middles. Consequently, lateral root growth is either mildly or greatly restricted depending on soil type. This surface compaction also slows the rate of water infiltration into the soil, thereby increasing water runoff, and carrying with it topsoil, nutrients, and pesticides. This results in increased pollution of our streams. Since fertilizer and pesticides are applied and remain on the soil surface in no-till crops, this water runoff becomes a serious problem by increasing pollution of our streams.
In about 15 to 20 percent of cultivated land in this country, the man made plow pan severely restricts plant growth. If it is compacted tightly enough, roots cannot penetrate it; therefore plant growth and yields are greatly restricted. The density of compaction is determined by the soil type. With no "hard pan" or other restrictions, a plant's roots can grow to a depth of 6 feet and a width of 4 feet within about 45 days after seed germination. However, when the compacted layer is such that roots cannot penetrate it, the plant must obtain all its nutrients and moisture from the earth above the compacted layer. Therefore, it must receive rain at frequent intervals in order to survive. But it can survive for a longer dry period if it is feeding off 6 feet of earth instead of only the 6 to 14 inches of soil above the compacted layer.
Numerous systems have been devised in an effort to overcome the inability of plants to penetrate the compacted layer, to generally prepare better seed beds, more and better rooting in the soil and to increase water infiltration, in order to thereby increase crop yield, to better preserve natural resources, such as top soil and the moisture content in the soil, and to lessen pollution of streams and the like. Relatively recent examples of such prior systems are found in Norris et al U.S. Pat. No. 3,170,421, issued 23, Feb. 1965, and Krumholz U.S. Pat. No. 3,701,327, issued 31, Oct. 1972.
The development of the Harden-Brown soil conditioning apparatus for the first time permitted a single apparatus to accomplish in one operation all of the results which had previously required multiple steps and/or machines. Specifically, in a single pass under no-till conditions (that is, the winter cover crop or the previous year's crop residue having been left in the field, being generally known in the agricultural industry as "trash" or "mulch"), the Harden-Brown soil conditioning apparatus has been able to cut through mulch in the area to be prepared as a seed bed, break up the compacted layer beneath the anticipated seed bed, fill the trench left by the subsoiler when breaking up the compacted layer with the broken up soil, fertilize and apply pesticides to the seed bed area, and work the soil to prepare the seed bed for planting.
Details of the construction and operation of an earlier improved Harden-Brown soil conditioning apparatus are set forth in above-mentioned U.S. Pat. No. 4,187,916, the disclosure of which is incorporated herein in its entirety by reference as though set forth in full hereafter.
The present invention accomplishes substantially better results with greater efficiency than did the older Harden-Brown apparatus. An important difference between the present invention and the older Harden-Brown apparatus lies in the location of the slot filler wheel. In known conventional devices, of the type described, for example, in the above-noted Brown et al '126 patent and Harden et al '916 patent, a slot filler member was located behind and in longitudinal alignment with the subsoiler. In conventional apparatus of this type, a presistent problem occurs in that in wet soils of many soil types, soil will stick or adhere to the slot filler member. This occurs because the slot filler member is running in soil that has been loosened by the subsoiler member. In this loosened soil condition, there is nothing to prevent soil from sticking or adhering to the slot filler member. The arrangement of the present invention solves and eliminates this problem by the placement of the slot filler member to one side of the subsoiler member. By this arrangment the slot filler member will run in firmer soil. As is common knowledge in the agricultural industry, less soil will adhere or stick to implements in soil that has not been tilled compared to soil that has been tilled. The arrangement of the present invention constitutes a significant improvement over known soil conditioning apparatus.
The novel relationship between the subsoiler and slot filler means discovered by the present inventor and incorporated into the soil conditioning apparatus described hereunder has produced unexpected advantages having far-reaching significance and application to all types of soil conditioning. An important feature of this invention resides in the manner in which the slot filler assembly and subsoiler assembly are mounted relative to each other and to the main frame or tool bar. Due to its angled configuration, the subsoiler is pulled downwardly into the earth as the entire apparatus is pulled forwardly by the tractor. The depth of penetration is controlled by the location of the tractor lift or, more commonly, by depth gauge wheels mounted to the tool bar. The slot filler assembly is mounted to the tool bar for independent movement relative to the subsoiler in a generally vertical plane. The slot filler assembly is biased in the downward direction; the downward biasing force combines with the downward pulling force of the subsoiler to pull the slot filler member into the soil beside the subsoiler-created slot, resulting in a better slot filling action, and preparation of a better seed bed and rooting environment. The present inventor has also discovered that the overlapping relationship of the slot filler member to the subsoiler, particularly when the slot filler member is also tilted downwardly toward the subsoiler, and/or angled inwardly toward the slot formed by the subsoiler, does a better job of filling the subsoil slot and results in the preparation of a better seed bed and rooting environment compared to known apparatus.
Another important feature which differentiates the present invention from the Harden-Brown and other prior art devices resides in the location of the bed preparation implements. One or more rotatable bed preparation implements are mounted to the tool bar and extend downwardly alongside the subsoiler to prepare a wider root bed in the top 6 inches of soil adjacent the seed bed prepared by the subsoiler and slot filler than was heretofore possible with known devices.
This wider root bed, which can be up to 36 inches wide per row, is created by the coulters working, disturbing, or tilling the surface or topsoil up to 6 inches deep in a no-till environment. The slot filler member and bed preparation implements work, disturb, or till the soil but do not incorporate the mulch, trash, or crop residue which is on top of the soil surface. This root bed, i.e., loosened soil with mulch on top, is an ideal rooting environment.
This loosened soil with a mulch on top has another important advantage, that of increased water infiltration. Research has shown that a mulch on the soil surface slows the movement of water, thereby allowing a longer period of time for water to percolate or infiltrate down into the soil. Research also shows that soil which has been loosened by plowing without subsequent tillage which will recompact; i.e., bottom or chisel plowing without disking, etc., will have a much faster percolation or infiltration rate than will the same soil after later tillage has recompacted it. This loosened soil will also hold a much greater amount of water per foot of soil than the same soil after later tillage has recompacted it. This increased capacity of the soil to retain more of the rainfall and store it in the soil for future crop use can produce a dramatic increase in crop yield in a crop year that has one or more rains with runoff followed by short periods of drought. In such cases, the extra water stored in the soil is often enough to keep the crop growing until the next rain.
Another unique feature of the present invention is the ability of the implement to clear away up to 100% of the trash from a 4 to 8 inch wide band in the middle of the seedbed. This trash free band where seed is deposited greatly increases the chances of good stand for four reasons. First, the trash free band allows a more uniform placement or depth of seed in the soil. Secondly, the less trash in this band where seed is planted enhances seed to soil contact. Third, trash in the seedbed area causes seedling diseases and increases the chance of insect damage. Fourth, less trash is partially incorporated in the seedbed. Trash sticking out of the soil acts like a wick in drying the soil out. This is a major problem with in-row sub-soil no-till planters that are presently available.
The present invention accomplishes this trash free band for a seedbed by the parabolic design of the subsoil shank and the relationship of the slot filler and seedbed preparation members to the subsoil shank. The more parabolic a subsoil shank, the more the surface soil tends to roll out to the side of the subsoil shank. As this surface soil rolls out to the side, it throws the mulch or crop residue out of the seedbed area. This is a disadvantage with all presently available no-till planters which have no way of moving soil back into the seedbed area. If no soil is moved back into the seedbed area, then the seed is planted in a furrow or depressed area. Practically all crops need to be planted level or on a raised seedbed. The slot filler and seedbed preparation members of the present invention move or push soil back into the seedbed area. Adjustments on the slot filler and seedbed preparation members determine how much soil is moved back into the seedbed area to allow planting on a level seedbed or on a raised seedbed up to 8 inches high. This ability to build and plant on a raised seedbed is another unique feature of the present invention.
Still further, the present invention is significantly more compact than the older Harden-Brown apparatus, thus enabling a tractor to lift the unit more easily. This shorter length has other advantages, particularly when a planter is trailed behind; in such case, the entire length of the combined bed preparation apparatus and planter is substantially less than the older type systems, whereby the combination is more maneuverable and the planter tracks around a curve better, to follow the bed and plant the seed in the center of the bed when following around a curve.